7 Superfoods to Boost Energy Levels Now

You've pulled an all-nighter – again -- and now you're dragging. But you can't afford to take a break from your intense schedule, if you want to keep growing your business. So, consider fueling up with so-called "super foods" to keep your energy up and stress level down. In email interviews, we turned to celebrated experts, including Drs. Mehmet Oz and Andrew Weil for seven such foods to seek out. No doubt, these healthful picks will help you think more clearly and focus more on your business far more than a doughnut and super-sized soda.

Salmon: Improve Alertness

How it helps energize you: Salmon is a good source of protein, which can help improve your alertness and performance. "It's also been linked to an improvement in overall brain health," says Dr. Mehmet Oz, bestselling author and host of the syndicated "Dr. Oz Show."

Almonds: Help Curb Cravings

Why it's so special: These nuts are packed with fiber, protein and healthy fat to fill you up and curb cravings. "In addition, the vitamin E in almonds is good for your skin and appears to guard against sun damage," says Lucy Danziger, editor-in-chief of Self magazine and author of The Drop 10 Diet: Add to Your Plate to Lose the Weight (Ballantine Books, 2012). "Bonus: New research has linked almonds not only to improved heart health but a lower risk of certain cancers, such as breast and lung."

How it helps energize you: Almonds prevent spikes in blood sugar and insulin, which means fewer highs and lows while you're working.

Green Tea: Healthy Coffee Alternative

Why it's so special: Green tea is loaded with antioxidants and catechins, compounds that may help reduce the risk of heart disease.

How it helps energize you: A smart choice for a midafternoon pick-me-up, "these same catechins are also believed to help enhance your mood," says Dr. Andrew Weil, founder of the Arizona Center for Integrative Medicine at the University of Arizona Health Sciences Center.

Avocado: Improve Your Concentration

Why it's so special: Beneficial for their good fat, avocadoes contain plenty of potassium. "Avocadoes also contain a monounsaturated fat called oleic acid, which can help to lower cholesterol," Oz says. "In addition, avocadoes boost the appearance of hair and skin."

How it helps energize you: The dual fiber and fat in this summertime favorite help keep insulin levels steady, making concentration easier.

Veggies: Avoid a Blood Sugar Crash

Why it's so special: These veggies, including cauliflower, cabbage, Brussels sprouts, watercress and kale, are nutrition powerhouses. "They all contain a variety of compounds, including indoles and isothiocyanates, which may offer protection against a number of chronic diseases, including cancer," Weil says.

How it helps energize you: The fiber in these crunchy vegetables helps stabilize blood sugar and insulin, preventing energy levels from rising rapidly only to crash down.

Dark Chocolate: Lower Stress

How it helps energize you: Eating dark chocolate may lower cortisol, a stress hormone associated with increased appetite and weight gain. "Dark chocolate (aim to eat the type that contains 70 percent or more cacao) may help improve blood flow to the brain and cognitive performance," Danziger says.

Berries: Keep You Focused

Why it's so special: Dark berries, including blueberries, raspberries and blackberries, are packed with antioxidants. "They also contain other health-promoting phytonutrients, including anthocyanins, a compound that may help to lower blood pressure," Weil says.

How it helps energize you: Packed with fiber, berries can keep you focused by controlling your blood sugar levels and helping you avoid a dip in energy.